For a step of a CR in a MES to unfold without problems, it is necessary that a strategy be found and realized on its landscape (even if, later on, it is proved not to be adapted). Let us consider a particular CR of a MES. The development of one of its steps can be interrupted, either because there is no available strategy, or because the selected strategy cannot be realized. In this case, we say that there is a fracture for the CR; then a new strategy must be chosen, possibly imposed by another CR. If the fracture is maintained during several steps, there is a dyschrony for the CR.

The fractures may come from constraints external to the CR, in particular imposed by the competition with the other CRs of the MES through the play among their strategies.

They can also result from the non-respect of the temporal constraints in the various phases of the step, in particular because of too long propagation delays and/or too short stability spans; in fact, propagation delays and stability spans are interdependent and act in synergy. Among these causes:

3. Lack of cooperation between the agents to select a strategy if the propagation delays of their distinguished links are too long or if the choice of a common strategy is difficult, for instance if some agents also belong to other CRs with opposed interests (obstruction in an assembly).

4. Inefficient commands to the effectors because of too long propagation delays or because of changes in their internal organization leading to a shortening of the stability spans. Then the strategy is only partially or not at all realized, with risk of fracture immediately or at the following step (lack of some pieces necessary for the construction of an object).

An important fracture, because of a real external perturbation, of a wrong perception of the situation or of conflicts between CRs, will not be repaired at the next step and will result in a dyschrony for the CR, with a risk that it be reverberated to other CRs. The repair may require an external intervention, either on the demand of the CR (call to the physician), or imposed to the agents, specially if the situation is blocked at some level. The repair can use already known strategies (in bacteria, intervention of the supramolecular system SOS (Radman 1975) to carry on the DNA replication, suspended because of to many errors). But if the situation is unknown, new strategies must be found, leading to various types of changes.

A possible change is the modification of the period of the CR, which is either lengthened or shortened, so that the structural temporal constraints can still be respected. We speak of a de/resynchronization for the CR.

In the theory of aging proposed in (Ehresmann & Vanbremeersch 1993), the senescence of an organism is attributed to a cascade of de/resynchronizations: the periods of CRs in higher and higher levels are lengthened, to neutralize the effects of longer propagation delays at lower levels, caused by an accumulation of external stochastic events not repaired soon enough. This process stops when the instability becomes too extensive (the period must always remain less than the stability spans).

On the contrary, during development phases, the periods are shortened thanks to the formation of more and more complex objects and to the storage in the Memory of complex strategies allowing quicker and more efficient responses.

Let us consider an enterprise in which one of the units, say C, produces screws necessary to other units charged of the assemblage of some instruments. A brief delay in C will easily be made up in the following days, before any disruption in other units. But if the delay in C persists, for instance by lack of enough workers, there is a dyschrony. And it will be reverberated to other units whose stocks of screws will not be renewed in time. Then these units will also have to slow down or even stop their production (technical unemployment). The situation will be repaired by the intervention of higher CRs (management), which may enroll more workers in C; or they may decide to automatize the production, possibly causing dismissals later on.